1. Field of the Invention
This invention relates to a method and apparatus for reducing the smoke and odor emissions from the kitchens of restaurants.
2. Description of the Prior Art
Ventilation systems for collecting and removing gases from the cooking area of a kitchen have long been known. The prior art systems vary from those which merely seek to remove the gases from the kitchen to more elaborate systems which seek to remove at least some part of the liquid and solid particles found in the gases before the gases are discharged into the atmosphere. Filters have long been used in domestic and commercial kitchen ventilator systems to remove grease from the gases passing through the ventilator system. Typically, the filters become filled with grease, and are a source of high risk from fire should the grease become ignited. The more elaborate kitchen ventilator systems include filter washers to periodically wash the filter. In large commercial kitchen ventilator systems after burners and electrostatic precipitators have been used to remove smoke and odors from the gases, but the high cost of energy and of maintenance required by these systems have deterred their use by the average restaurant operator.
When the Clean Air and Water Act was passed in 1970, standards for clean air were set by federal, state, and local governments which made most restaurant kitchen ventilator systems inadequate. As a consequence restaurant operators began to consult with restaurant kitchen ventilator system suppliers and found that easily maintained, and reasonably priced kitchen ventilator systems which would meet the new pollution control standards were unavailable.
It is recognized that coalescing filters are old in the art. A coalescing filter is one which causes small liquid particles carried by a fluid steam to collect on the filter and grow into larger particles. Frequently the larger particles of liquid become sufficiently heavy to flow by gravity to a collecting chamber or area. One coalescing filter which is commercially available is disclosed in U.S. Pat. No. 3,540,190 which was issued to Joseph A. Brink, Jr. on Nov. 17, 1970 and is assigned to Monsanto Enviro - Chem Systems, Inc. The filter disclosed in U.S. Pat. No. 3,540,190 has particular use in systems for the removal and recovery of acid mists from process streams but it is indicated to have applications of more general use.